E. Limiti

ABSTRACT Constant input and output mismatch circles in the output load plane are introduced as the basis for low-noise amplifier design methodology. Optimum tradeoff between input and output matching levels results as the application of a design chart providing, at the same time, the corresponding stage transducer gain. The role of degenerative series feedback is studied and systematically embedded in the design procedure, thus providing a direct way to evaluate its optimum level.

Abstract In this article, the minimization of asymmetry between lower and upper side band intermodulation products is discussed. Base-band and harmonics termination effects are analyzed by means of a Volterra Series approach, identifying novel conditions to minimize IMD asymmetry and IM 3 power levels. The new inferred conditions do not involve base-band terminations, but harmonic load conditions. The proposed criteria are experimentally validated through harmonic load-pull measurements performed on a GaN HEMT under ...

ABSTRACT In the framework of silicon (Si) technology, evolution towards high-frequency analog applications – which involves innovative solutions such as SiGe BiCMOS and FinFET devices – wide bandgap semiconductors grown on Si substrates are likely to represent a valid option in those cases wherever high-power handling and low noise figures are required. Although such active devices have been extensively investigated in the last years, much of interest has been devoted in developing nonlinear models for high-power applications, whereas reliable noise models still lack, in particular, the validity of traditional (i.e. equivalent temperature-based) approaches for noise modeling of wide bandgap devices has not been sufficiently probed yet. In this contribution, a quite general, black box noise model of active devices is proposed and applied to a family of gallium nitride-on-Si high-electron-mobility transistors fabricated by Selex ES. The model is based on a polynomial approximation of the device correlation matrix and does not require that an accurate small-signal equivalent circuit is available; instead, it can be extracted from multifrequency source pull data. Experimental results demonstrate that a typical behavior of the noise parameters is obtained, both versus frequency and gate periphery. Copyright © 2013 John Wiley & Sons, Ltd.

Abstract Gallium Nitride's superior physical properties, in comparison with other semiconductors, make GaNHEMT active devices a prime candidate in the implementation of next generation transmitters for radar systems, 3G/4G base stations and WiMAX. In this contribution, the characterization, modelling and verification of different families of high efficiency, high-power devices manufactured at SELEX Sistemi Integrati are reported. Process, characterization and modelling phases are analyzed to improve and refine the ...

In this paper a new test bench for the measurement of FETs dynamic output I/V characteristics is presented. The characterization is carried out generating asymmetrical voltage signals at the gate of the device while the load at the drain terminal is varied. The experimental results obtained performing on-wafer measurements of a 1 mm GaAs PHEMT using the proposed test bench,

A core-chip for X-band applications with on board serial-to-parallel conversion implementing a separate architecture topology is presented. The main RF performances are 10dB gain at minimum attenuation, 0-360° phase coverage, 0-31.5dB gain setting in less than 15mm2, resulting in one of the smallest core chips realised in GaAs technology. The slight parasitic cross-effect between phase and gain setting is also described showing that the component can be used in beam forming networks for phased array applications without necessarily having to pre-calibrate at system level.

ABSTRACT A novel narrow-band design methodology for multi-stage low-noise amplifiers (LNAs) is presented which is based on noise measure and on appropriately designed reactive inter-stage networks. Design formulae are given, in particular, concerning the realisation of the latter networks in T and II configurations, so as to make possible a partially automated design algorithm. As a test vehicle of the presented procedure, the design and realisation of a three-stage K-band LNA is discussed and the corresponding measured results are shown.

Abstract— In this contribution the possible applications, technology, design and measurements of a W-Band high gain LNA are given. The main features of the four stage LNA can be summarised as following: a 25dB average gain with ±2dB ripple from 70 to 105GHz, where gain is ...

In this contribution, the design of an X-Band MMIC Doherty Power Amplifier (DPA) in GaAs technology is presented. The DPA, based on 2250μm of total gate periphery, will be deeply described with the aim to highlight each design choice. The nonlinear simulation results shown a saturated output power and drain efficiency greater than 30dBm and 47%, respectively. Moreover, in the

The realisation of a power amplifier (PA) simultaneously maximising output power (Pout) and linearity performance (CI13) is a fundamental challenge in transmitter systems design. If Pout and drain efficiency (q) performance is concerned, an established solution consists in ...

Sub-micron gate length Metal Semiconductor Field Effect Transistors (MESFETs) have been realized on polycrystalline diamond samples supplied by Element Six Ltd. and by Russian Academy of Science. RF performances are shown for devices realized on polycrystalline diamond samples of different quality, stating the successfully improvement and reliability of realization technology.

Citazione: Colantonio, P., Giannini, F., Limiti, E., Orengo, G., Scucchia, L., Serino, A., et al.(2005). Microelettronica a radio frequenza per applicazioni spaziali. In ElEm 2005 XI Giornata di studio sull'ingegneria delle microonde.

Waveguide transitions are frequently used in telecommunications hardware to interconnect rectangular or circul ar waveguides feeding the reflector antennas with internal active circuits, often realized in MMIC technology with microstrip, coplanar wave guide and other guiding structures. In this contribution, the effects of m anufacturing tole rances on this kind of transitions are an alyzed b oth in qualitative ter ms and i n quantitative ones using a Monte Carlo method applied to FEM electrom agnetic simulations. Measures on a W-Band prototype are used to validate the approach.